There are practically used devices so called a micro analysis chip, or a μTAS (Micro Total Analysis System) in which a micro-channel and a circuitry are formed on a silicon or a glass substrate via a micro technology so as to perform a chemical reaction, isolation and analysis of liquid specimens such as nucleic acid, protein and blood in a micro space. As a merit of the micro channel chip, it is considered that there is realized a space saving, portable and economical system which reduces amounts of sample and reagent used and an emission amount of waste liquid.
The microchip is manufactured by bonding two members wherein a microstructure is formed at least one member. Conventionally, a glass substrate is used for the microchip and various forming methods of forming the micro structure are suggested. However, since the glass substrate is not suitable for mass production and very costly, development of a low cost and disposable resinous microchip has been desired.
To manufacture the resinous microchip, a resinous substrate having a channel groove on a surface thereof and a resinous film to cover the channel groove are bonded. In the resinous substrate having the channel groove, through holes penetrating in a thickness direction of the resinous substrate are formed at ends of the channel groove and the like. The resinous substrate having the channel groove on the surface thereof is bonded with the resinous film for a cover with the channel groove inside. By the above bonding, the resinous film for the cover serves as a cover of the channel groove, thus a channel is formed with the channel groove and the resinous film. Whereby, the microchip having the channel inside is manufactured. Via the through holes formed on the resinous substrate, the channel and an outside of the microchip are connected, and liquid specimen enters and exits via the through holes.
As the method to bond the resinous substrate and the resinous film, there are cited a method to use an adhesive, a method to dissolve the resin surface for bonding, a method to use an ultrasonic welding, a method to use laser welding, and a method to use thermal fusion bonding via a pressure device having a role shape or a flat shape. Among the above methods, thermal fusion bonding is suitable as a bonding method, assuming mass production since it can be practiced at a low cost
As the above microchip, there is suggested a microchip in which onto an acryl family resinous substrate such as polymethylacrylate, the same acryl family resinous film is bonded via thermal fusion bonding.